Something happened. I stopped by the pharmacy to pick up a prescription, and a nurse asked me if I’d like to get my flu shot. HECK NO, I thought, because I find injections and blood draws to be terrifying and I like to have a few days to scrape together some courage. I thought October was the earliest that flu shots were available, and no way was this sneak attack on my mind in summer! What I actually said was, Sure, let’s just get it done. I know when I’m being a coward and I’m actively trying to suppress that part of myself. That’s why I started training in martial arts for the first time back in January. I didn’t realize that these two unrelated things would turn out to be connected.

First off, for the skeptics, let me share why I get the flu shot in the first place. I used to avoid it, just like, once upon a time, I believed that homeopathy must be valid because they sell homeopathic products at the natural foods store. (*facepalm*) Then one year my husband got a flu shot at work. I considered getting one, but I “never got around to it” because of course I would do anything to avoid having a needle anywhere near my body. I got really sick that year and my husband didn’t. I was down for eight days while he continued to go to work, whistling a happy tune and obviously feeling fine. That does it, I thought. I’m getting the flu shot every year from here on out.

I’ve gotten the flu shot every year for the past, I think, five years now? I don’t know what terrifying things people think will happen to them if they get a flu shot, but none of them have happened to me. I’ve been immunized against everything I can be, including tetanus and hepatitis, two common infections that I really, really don’t want. Intellectually, I’m convinced of the benefits of herd immunity, and my contribution to protecting little infants, cancer patients, and other immune-compromised people who can’t get vaccinated even if they want to.

Emotionally, it’s still been very tough for me to march myself in there and ask for an injection. Even the smell of rubbing alcohol would make me woozy. The sight of rubber tubing or any of the other apparatus, and even the mint-green color so common on scrubs would set me off. I would have to put my head between my knees afterward, even if I had the chance to lie down during the procedure.

Last year, when I got my flu shot, my husband and I walked from the hospital to the movie theater about a half mile down the street. I was sitting in the lobby with my head between my knees for twenty minutes, but if we stayed longer, we would miss our show. I was so wobbly that just a block from the hospital, I had to sit down in the grass and wait while he went to a convenience store and got me something to raise my blood sugar.

When I say that I have a needle phobia, I’m really not exaggerating.

That’s why it surprised me so much when I got my flu shot this year. As we walked into the ordinary conference room where this operation seemed to be proceeding, I informed the nurse that I get needle reaction and that I’d have to cover my face. She said that happened all the time and not to worry about it. She swiped my arm with rubbing alcohol, I braced myself, the needle went in... and maybe one second later, it was over. That’s it? I asked. I couldn’t believe it. The bandage went on and I was released.

I kept waiting for something to happen. I thought I’d feel the usual nauseating rush of dizziness that I’ve had since childhood. I was sure I’d have to sit there with my head between my knees and possibly risk missing my bus. I thought I’d embarrass myself, like I do every year, by collapsing and making a spectacle of myself. But... it was... totally fine. I can’t even really say it hurt.

My husband and I texted about it. “I think martial arts is doing things to me,” I said. “I know it is,” he replied.

What’s going on with this? What is happening to me after eight months of martial arts training in Muay Thai and Krav Maga?

Stress inoculation is one factor. This is the simple idea that repeated stressors gradually become less stressful through exposure. It’s the principle behind why Toastmasters helps people like me who are afraid of public speaking. It’s also quite true for physical pain, as I’ve learned in the mat room. I have been accidentally socked in the nose, mouth, and eye multiple times, and found that it either barely bothers me or actively seems funny. This never would have been true in the past.

Body composition may come into play. I have more muscle than I ever have before. There may be other components, too, like bone density, vascularity (more and stronger blood vessels), glycogen storage, or hormone balance. No idea, but it’s objectively testable.

Another possible factor is my resting heart rate. My resting heart rate has apparently been abnormally high since middle school. I didn’t really make the connection until I started wearing an Apple Watch. Every prior time that a health professional expressed concern about my heart rate, we would decide together that my fast walking to the facility was responsible. I couldn’t buy that rationale anymore, not with three years of tracking data. At 43 years of age, I felt like I needed to take my heart health as seriously as possible, and I researched how to improve my resting heart rate. HIIT, or high intensity interval training, came up as a viable method. That’s what we do in martial arts, especially during warmups. I’ve been training long enough now to notice a discernible downward trend in my numbers, and it’s possible that this adjustment has impacted my anxiety level around my needle phobia.

Maybe I’ve just been psyching myself out all this time. Maybe spending days or weeks dreading an impending injection would just put me in a stress state. I’m not sure about that. One year in college, I was in the health center, and records indicated that I was due for a tetanus shot. They had my ID and wouldn’t let me leave until I got it done! (Maybe I could have signed some form releasing them from liability or insisting that I refused a tetanus shot, I don’t know. But I did understand that I needed one and intended to comply... laaaaterrrrr...). I didn’t have any time to slink away and mentally compose myself, and I have to say that my panic and pain were just as intense as any other time, maybe more so, because tetanus shots hurt.

What I think is one of the biggest factors here is that my pain threshold is significantly higher. Some stuff I’ve been reading recently suggests that pain is controlled more by the central nervous system than it is by any specific body part, injury, or illness. This makes a lot of sense and feels consistent with my experience recovering from fibromyalgia. It also seems to fit with my impression that athletes in general have a higher pain threshold. I assumed they started with some kind of genetic tendency to feel less pain, allowing them to crash into each other in team sports. Now I believe the opposite, that sports training increases the pain threshold, and that this transformation may be available to anyone at any age.

Further, I have a suspicion that this is some kind of long-lasting neurological change. The reason I think this is that after a year or so of distance running, I quit having a problem with depression. It’s never come back, even though I basically quit running a few years ago. There seems to be something really interesting going on with a certain level of very strenuous physical activity over an extended time period. If running can change what felt like a personality-level issue with something as serious as depression, then it feels consistent that martial arts can change what also felt like a character-deep, yet minor, issue with a needle phobia.

At this point, I’m training out of fascination and curiosity, because there’s so much to learn, because I have friends at my gym, and because it’s starting to be fun. There are enough interesting physical and possibly neurological changes that I’m also following those trends with keen attention and interest.